1. Field of the Invention
This invention relates to an improved structure of feeding bottle, particularly to a feeding bottle that is provided with a thoroughly opened bottom opening for easy cleaning, a hard ferrule to pack a ventilative gasket and prevent it from detaching to keep the feeding bottle always in normal operation.
2. Description of the Prior Art
A conventional structure of feeding bottle has been disclosed in U.S. Pat. No. 4,723,668, wherein a flexible ventilative gasket is disposed to bottom of a feeding bottle, and a crossed cut is made in the ventilative gasket. When an infant is sucking milk, the air in the bottle will flow out of the bottle accompanying the milk, so that the air pressure in the bottle is decreased, and outside air will flow into the bottle to balance the air pressure inside and outside. The defect is that the small inward-shrinking crossed cut in bottle bottom may curb the cleaning job.
In another U.S. Pat. No. 57694, a ventilative gasket used to cover on bottom opening of a bottomless feeding bottle is locked by a swivel bottom closure. This disclosure can facilitate cleaning on the one hand all right, however, a ventilative gasket disposed to the bottle bottom is packed only by a small ring area of the bottle wall in 0.2 cm thick that can hardly pack the ventilative gasket on the other hand. Hence, in the case when relatively stronger sucking force is required, such as feeding an eider infant or feeding with thicker juice or the like, the ventilative gasket may be deformed to bulge like a semi-sphere or even detached from the bottle bottom to result in leakage or become functional disabled.
As disclosed in Japan patent No. 120285, an inward-shrinking opening is also formed in bottle bottom with an extra narrow packing ring in 0.2 cm thick for constraining a ventilative gasket. The defect of this disclosure is about the same with that in abovesaid U.S. Pat. No. 57694 for lack of a leakage-proof function.
Another U.S. Pat. No. 14739 is to perforate a small vent in bottle bottom with a ventilative structure plugged therein that makes cleaning job uneasy, then seal the vent with a bottom closure. The plug introduces another problem--if the plug is made of the same hard material with the bottle body, the combining edge cannot completely sealed, and on the contrary, a clearance will comes out when a relatively hotter liquid is loaded in the bottle due to different expansion coefficients of the plug and the bottle body to cause leakage; and further, after the bottle is sterilized in high temperature, the structure will be deformed and damaged permanently.
Similarly, a further U.S. Pat. No. 2,139,903 is to form small vent in bottle bottom or in bottle wall and use a vertilative plug to seal the small vent that incurs a defect as abovesaid U.S. Pat. No. 14739 has done.
Furthermore, a U.S. Pat. No. 3,134,495 with a complicated structure in relatively higher cost is also to open a inward-shrinking opening in bottle bottom that curbs cleaning job as mentioned above. In addition, according to its illustrating diagrams, when the bottle is filled up with milk, the center of gravity will locate at an upper position to set the feeding bottle in an unstable state.